The hungry sheep look up, and are not fed,
But, swoln with wind and the rank mist they draw,
Rot inwardly and foul contagion spread….
— John Milton, “Lycidas,” 1637

His name was Stephen Churchill, and he was just 19 when he died. A native of the U.K., this teen was one of the first known human cases of vCJD.¹ He succumbed to this deadly disease after developing jerky movements and progressive hallucinations that engulfed him in a horrifying dementia that replaced his sense of reality with movie screen images of fires and floods. It’s no wonder panic set in.

Some common denominators in the first patients with this frightening disease — average age 27 years — were slow waves on EEG and large, rounded plaques in brain tissue. Case reports reveal that early manifestations included psychiatric symptoms such as anxiety, depression, and social withdrawal along with sensory symptoms such as dysesthesia and paresthesia. Later symptoms included gait disturbances, slurring of speech, and tremors, followed by chorea, dystonia, and myoclonus.² Patients are symptomatic for at least six months prior to death.³ IN the U.K., where 162 cases were reported, the major source of contamination appears to be beef.³

Emergence of a new disease

BSE, or mad cow disease, first appeared in England in 1984. Since then, an extremely rare human equivalent emerged — a new strain, vCJD. Suspicions link human cases to the ingestion of beef products containing bovine central nervous system tissue.⁴ How often vCJD will strike is uncertain because the extent of cattle products in human food has been largely unregulated, and no human screening test has been developed. Not only could apparently healthy persons be incubating the disease, but transmission iatrogenically (through surgical and medical diagnostic instruments), with pharmaceutical and dietary supplement products, and via blood and organ donations could be taking place. Although the risk of acquiring vCJD is probably low, global and national efforts are under way to control the extent and distribution of the infectious agent.

It was noted that Churchill’s symptoms were similar to those present in patients with kuru in Papua, New Guinea.¹ Epidemic in 1957, kuru in the native language means “to tremble with fear,” reflecting an early symptom of cerebellar ataxic gait. A Nobel Prize in medicine was awarded to the Americans who tracked the uncoordinated, staggering, and wide-base gait of the afflicted persons to the cannibalism of their deceased relatives — an act of homage by descendents. The illness mainly affected women and children, who ate organs and brains, rather than men, who ingested muscle. Although the disease faded with the end of cannibalism in the 1960s, a few victims occasionally crop up because of the long incubation period.

The U.S. has recorded a disease with similar neurological manifestations — progressive multifocal leukoencephalopathy, caused by the reactivation of a latent human Polyomavirus JC — in a small number of immunocompromised patients with AIDS.⁵ And scientists have known since the 1920s about sporadic CJD that results iatrogenically from contaminated surgical equipment and pharmaceutical agents, such as cadaveric human growth hormone, and from natural mutation.^6,7 About 250 iatrogenic cases occurred, but because of stringent infection control and product monitoring, none have been reported since 1976.⁸ However, the cases of Churchill and other young British citizens like him are different. This epidemic of a progressive neurodegenerative fatal disease in humans involves a new variant that seems to be connected to a cattle epidemic of BSE that entered the human food chain.

From sheep to cattle

Mad cow disease may have arisen spontaneously or spread from sheep afflicted with scrapie, an endemic spongiform encephalopathy. It seems that around 1980, after all consumable parts had been removed from livestock (including sheep), the carcasses were milled for use in the animal food industry. It is thought that the rendering process may have allowed the etiological agent in infected carcasses to survive, infecting the cattle that subsequently consumed it.⁴ As the chain continued, cow products have been used not only as feed for household pets and zoo animals, but as foods, dietary supplements, and components of plasma and blood products for humans. Cow products, such as bone meal, are also used in pharmaceutical agents (injectable drugs and vaccines), gelatin (gel caps, hard capsule shells, and glossy pill coatings), and cosmetics. These products, shipped all over the world, have been unregulated until recently.

In the late 1980s, the banning of the import and export of all beef products and the feeding of almost all categories of animal remains to cows and sheep in BSE-affected areas began to bring the epidemic under control. In addition to the loss of 200,000 diseased animals, the U.K. destroyed four-and-a-half million more asymptomatic cattle.⁴

Fear realized: cattle to humans

As of January 2007, as mentioned above, 162 human cases of vCJD have been reported in the U.K. thus far. Twenty cases have been reported in France, four in Ireland, and two in the U.S. The patients from Ireland and the U.S. had lived in the U.K. for more than five years during the U.K.’s BSE epidemic. One case each has been reported in Canada, Italy, Japan, Netherlands, Portugal, Saudi Arabia, and Spain.³ Human infection in Britain probably resulted from beef products contaminated with nervous system tissue from cattle. Cuts of meat containing vertebral tissue, such as T-bone steaks, can contaminate human food. The presence of residual cattle spinal cord and paraspinal ganglia tissue in the paste of mechanically recovered meat, a carcass compression extract that could legally be added to cooked meat products like meat pies, beef sausages, and canned meat preparations, can also taint food.⁴

Although cattle ingredients are used in many drugs, such as surfactants,¹⁰ the largely unregulated dietary supplement industry is a big concern. Hundreds of products use an array of cow tissue, from ground prostate glands and testicles in supplements to bolster sexual vitality to freeze-dried brains and pituitary glands in supplements that allegedly stimulate memory. The labels of only about 7% of these products indicate the inclusion of animal parts. Some products sold in the U.S. may contain cattle brains, glands, or spinal cords.

All eyes are on the patient count and surveillance efforts in Britain, the epicenter of the epidemic. Case reports will yield clues about the extent of the problem and the risk in other countries, including the U.S. Each patient case is studied. Tissues of animals are tested to assess preclinical infectivity, and new tests for BSE in cattle are being evaluated. Although the number of infected cattle reported from the U.K. has dropped, fear, panic, and anger over the threat of BSE and vCJD to economic, political, agricultural, and physical health have arisen in Europe. For example, in Spain, beef consumption plunged by 70% when the first case appeared in November 2000.¹⁰

Mad cow comes to the states

Concern smoldered in the U.S. where in 2000, the Food and Drug Administration ordered the destruction of one potentially contaminated lot of polio vaccine.⁴ When a presumptive diagnosis of BSE was made on a single cow in Washington on December 23, 2003, the heat was on to protect the human food supply. The cow’s herd was immediately placed under a state hold order and the U.S. Department of Agriculture (USDA) recalled beef slaughtered from the same plant on the same day that the BSE-positive cow was slaughtered. The day in question was two weeks prior to the diagnosis.¹⁰

The recalled beef, including that from the BSE-positive cow, had already been released, processed, and shipped to locations in Oregon, Washington, California, Idaho, Montana, and Nevada. As part of the USDA’s targeted surveillance for BSE, brain samples were collected from the cow at the time of slaughter as it was a “downer” cow, or nonambulatory. Its condition was thought to be due to complications from calving. Although the carcass had been released for human consumption, the brain, spinal cord, and small intestine had been removed and sent for inedible rendering. These potentially infectious tissues, which are sometimes used as feed for nonruminant animals, were located. In addition, the plants that processed them placed a voluntary hold on these products as of January 7, 2004.⁹

Trace backs and precautions went beyond the two-week period between time of slaughter and diagnosis of BSE. The origins of the BSE-positive cow were traced to Canada, from which it entered the U.S. as one of a group of 81 cattle in 2001.¹⁰ The USDA is investigating the whereabouts of these cattle in addition to 17 more from the BSE-positive cow’s birth herd that may have crossed the Canadian border as part of a later shipment.¹¹

As a result of this single case of BSE in the states, the USDA announced more stringent measures to protect the food supply. Nonambulatory cattle are not allowed for human consumption. Any carcass tested for BSE is not marked as “inspected and passed” until negative test results are received. A number of changes in processing were also required to eliminate the potential for contamination of beef used for human consumption.⁹ Since that time, sporadic cases of BSE have been identified in the U.S. and Canada, but none have entered the food supply. The USDA maintains that the food supply is no less safe than it was before the discovery of the cow. The ban on feeding of mammalian protein to ruminants in the U.S. since 1997 and ongoing surveillance for BSE will continue to minimize the risks related to beef consumption.

Fatal possibilities — the prion

It’s not a bacterium, virus, or fungus causing the disease, but probably an unconventional transmissible agent called a prion. A prion is a “small infectious particle, which is a modified form of normal cellular protein.” In addition to being infectious, prion diseases are also believed to have a link with heredity.¹²

It started with an obscure paper in a 1967 mathematics journal that predicted how protein could be an infectious agent by self-replicating.¹ The author postulated that a rogue protein could bind with a normal protein, making a new one with a unique shape that could grow exponentially to form space-occupying fibers or threads. In 1997, Nobel Prize winner Stanley B. Prusiner lent further credibility to this notion.

All patient deaths suspected for vCJD are investigated and autopsies performed. What researchers do know is that the amount of infectious tissue ingested, plus a genetic predisposition, seem to be a determinant for transmission.⁴ As yet, no cases of vCJD have originated in America.

When patients express concern, we can say that —

1. There is no evidence of transmission by blood or blood products.
2. There is no evidence of transmission via patient care.
3. There is no evidence of person-to-person transmission.

The Joint Commission reacts to CJD

The Joint Commission has also responded to the possibility of vCJD showing up in the nation’s hospitals by publishing a Sentinel Event Alert on the subject. The Joint Commission publishes a Sentinel Event Alert when it becomes aware of a clinical issue or a trend that has significant patient safety implications for their accredited hospitals. The Sentinel Event Alert on vCJD provided two recommendations: (1) that policies be developed for the disinfection or disposal of instruments used in neurosurgery in general and when vCJD is suspected or confirmed, and (2) that such surgical instruments be quarantined until an unclear diagnosis or biopsy is clarified.¹³

The Joint Commission expects all of its accredited hospitals to evaluate their current practices against the vCJD Alert recommendations and make any changes necessary to become compliant. When The Joint Commission surveyors conduct a hospital’s survey, they will expect to find full adoption of the Alert’s recommendations.

Taking action

So far, no human-to-human transmission of vCJD has occurred. However, the possibility of iatrogenic spread, that is, by medical and surgical equipment, is more likely if large numbers of infected people are silently incubating the disease.⁴ Because of the theoretical possibility of widespread infection in the U.K., consideration extends to the safer use of medical and surgical instruments, particularly those used in neurological and ophthalmic surgery.⁴ Disposable equipment is to be used whenever possible. The most stringent disinfectants are used as a standard sterilization protocol for reusable equipment.⁸ Complete guidelines are available from the World Health Organization .

Blood is also a major concern. Although no evidence supports transmission in this manner, several governments have implemented policies to minimize the risk for human-to-human disease transmission through blood donations from apparently healthy persons who may be in the incubation phase of vCJD, which can last 10 to 15 years.² For example, all plasma is imported in the U.K., and any blood from U.K. donors is filtered to eliminate leukocytes, the most likely carriers of infectivity in blood. In the U.S., a blood donor policy excludes donations from anyone who has lived in or visited the U.K. for a cumulative period of six months or more during 1980 to 1996 and from direct descendents of vCJD victims.⁴

The current risk of acquiring vCJD from eating beef muscle and beef products produced from European cattle cannot be precisely determined. And this risk in specific countries might not reflect the fact that cattle products from one country might be distributed and consumed in others.⁴ Nevertheless, in the U.K., this current risk appears to be extremely small, perhaps about one case in 10 billion servings. To reduce the risk of acquiring vCJD from food, the Centers for Disease Control and Prevention (CDC) recommends that when traveling to Europe, you may wish to consider —

• Avoiding beef and beef products altogether.
• Selecting beef that might have a reduced opportunity for contamination with tissues that might harbor the BSE agent, such as solid pieces of muscle meat versus beef products like burgers and sausages.

Concerned travelers to Europe can be referred to a travel clinic to discuss CDC and World Health Organization recommendations with an expert in global health and infectious diseases.

Why such a confounding condition?^1,4,6

Here are just some of the reasons that vCJD has stumped medical science so far:

Genetic Susceptibility: The human genotype at polymorphic codon 129 of the PRNP gene appears to play an important role in susceptibility to infection. However, some may be initially more resistant, but become ill after longer incubation.

Inoculum Dosage/Infectivity: The “trigger” dose — how much needs to be ingested to cause infection — in humans is unknown.

Dose Effect: No one knows if the disease results from a cumulative or proportional dose effect. It is not known if a specific time span is required for adequate inoculum dosing.

Undetermined Prevalence: Because the number of originally infected cows is unknown, no one can accurately extrapolate how many humans were potentially exposed.

Unknown Disease Reservoirs: It is unknown if the culprit is located only in the brain and spinal cords of cows, or if it affects other organs, glands, and muscles.

RNs quelling the fear

Nurses need to be prepared for uncertainty, concern, anger, and fear. To be fully equipped, nurses need to arm themselves with information — FDA regulations and CDC recommendations. Pay attention to the use of bovine products in pharmaceuticals, cosmetics, and food and to concerns in blood bank industries so you can anticipate and address patient inquires.

Be aware of patients who may be more alarmed than others, including those who have lived in Europe; those who are suspicious of the pharmaceutical, meat distribution, or supplement industries; family members of vCJD patients; and even other healthcare workers. Some individuals may view it as “payback” for society’s valuing of industrial needs over environmentally judicious behavior. In others, it may provoke concerns about the safety of equipment used in surgical procedures.

To stay on top of the issues, nurses also need to be aware of two other animal-related illnesses — chronic wasting syndrome and foot-and-mouth disease. The simultaneous occurrence of these diseases may fuel the fires of concern over mad cow disease. It is also essential to be aware that the classic form of vCJD occurs worldwide and is not related to the BSE epidemic in the U.K. It generally presents at an older age than vCJD and is just as fatal.⁸ The CDC has a useful table comparing the two conditions .

Chronic wasting disease is spreading rapidly among deer and elk herds, captive and wild, in six Western states and in Canada. In vitro, chronic wasting disease has been shown to infect human cells. Although never proven, hunters and their families who have eaten infected deer or elk meat could have the disease and potentially spread it via donations of blood or organs.¹⁴

Faced with the first outbreak in 20 years of foot-and-mouth disease, British officials temporarily suspended all exports of live animals as well as milk and meat, beginning in February 2000 until the outbreak is under control. Foot-and-mouth disease, which generally strikes cloven-foot ruminants like sheep, pigs, goats, deer, camels, and cows, is a highly contagious viral illness that can be spread by minimal contact and even through the air. The disease rarely affects humans and does not cause death. In the U.K., the disease is generally called hoof-and-mouth disease.

While these diseases won’t affect your day-to-day practice, nurses must be prepared to address patient, family, and public concerns, especially when it comes to vCJD. Remember that nurses are in a great position to help patients gain a sense of power by using therapeutic communication strategies, such as clarification, open-ended questions, and feedback, reflecting content and feelings back to the patient for their consideration and summarizing patients’ concerns.

Once updated on the issues, you can provide information to assuage unrealistic worries. But as with all health-related concerns, we need to investigate our own feelings and attitudes about this new epidemic first. Nurses have a responsible role in society. Drugs that may be useful in combating the disease in humans are already being tested in animals. Let’s proceed confidently.